Types of Hearing Loss: Sensorineural, Conductive & More
Not all hearing loss is the same. The type you have determines the cause, the treatment options available to you, and whether any of that loss can be recovered. Here is what each type actually means - and why the distinction matters.
Why Knowing Your Type of Hearing Loss Matters
Hearing loss is not a single condition. It is a category that covers a wide range of underlying causes, mechanisms, and anatomical locations - and the treatment that makes sense for one type can be entirely wrong for another. Two people can have the same degree of hearing difficulty and yet have completely different diagnoses, different prognoses, and different paths forward.
Most people who notice hearing difficulty don't think in terms of types. They notice that conversations are harder to follow, that they turn up the TV more often, or that they feel exhausted after social events. What they don't always know is that before any of those experiences can be addressed effectively, the type of hearing loss needs to be established - because that single distinction shapes everything that follows.
The four types of hearing loss recognized by the Centers for Disease Control and Prevention (CDC) and by audiologists worldwide are: sensorineural, conductive, mixed, and auditory neuropathy spectrum disorder (ANSD). Each is defined by where in the auditory system the problem originates.
Understanding hearing loss starts with understanding how hearing works. Sound waves enter the outer ear and travel down the ear canal, where they cause the eardrum (tympanic membrane) to vibrate. Those vibrations pass through three tiny bones in the middle ear - the malleus, incus, and stapes - into the fluid-filled inner ear (cochlea). Inside the cochlea, specialized hair cells convert those fluid movements into electrical signals that travel via the auditory nerve to the brain, where they are interpreted as sound. Hearing loss can interrupt this chain at any point - and where the interruption occurs determines the type of hearing loss.
Sensorineural Hearing Loss (SNHL)
Sensorineural hearing loss is the most common type of permanent hearing loss. Johns Hopkins Medicine identifies it as a problem within the cochlea itself or along the auditory nerve pathway - specifically, damage to or absence of the hair cells inside the cochlea that are responsible for converting sound vibrations into electrical signals the brain can interpret.
When those hair cells are damaged, the auditory signal reaching the brain is degraded. Sounds may be audible but unclear. High-pitched consonants - the sounds that carry most of the intelligibility in spoken language - are typically the first to be affected. This is why people with sensorineural hearing loss so often say that they can hear people speaking but struggle to understand what is being said, especially in noisy environments.
What Causes Sensorineural Hearing Loss
The NIDCD and Cleveland Clinic identify the following as the leading causes of sensorineural hearing loss:
- Aging (presbycusis). The most common cause overall. Age-related hearing loss affects roughly one in three Americans between 65 and 74, and nearly half of those over 75, according to the NIDCD. The loss is typically bilateral (both ears), gradual, and affects high frequencies first.
- Noise exposure. Noise-induced hearing loss (NIHL) is the second most common cause of sensorineural hearing loss globally, affecting an estimated 5% of the world's population (Journal of Clinical Medicine, 2023). A NIDCD and CDC analysis found that approximately 24% of U.S. adults aged 20 to 69 show audiometric signs consistent with noise-induced hearing loss - many of them without realizing it.
- Genetic and inherited factors. The AAFP identifies inherited disorders as a leading cause of sensorineural hearing loss. Genetics can cause hearing loss present at birth (congenital) or trigger loss that develops later in life.
- Ototoxic medications. Certain drugs damage the hair cells of the cochlea as a side effect. These include some aminoglycoside antibiotics (such as gentamicin), some chemotherapy agents (particularly cisplatin), high-dose loop diuretics, and high-dose aspirin. The damage can be temporary or permanent depending on the drug, dose, and duration.
- Viral infections. Certain infections, including mumps, measles, meningitis, and cytomegalovirus (CMV), are known to damage inner ear structures and cause sensorineural hearing loss.
- Head trauma. Temporal bone fractures, which can occur in serious head injuries, may disrupt the cochlea, the auditory nerve, or both - causing immediate and sometimes severe sensorineural hearing loss.
- Acoustic neuroma. A benign, slow-growing tumor on the auditory nerve (also called vestibular schwannoma) can produce progressive unilateral sensorineural hearing loss, often accompanied by tinnitus or balance problems.
- Ménière's disease. A disorder of the inner ear involving abnormal fluid regulation, causing episodes of vertigo, fluctuating hearing loss, tinnitus, and ear fullness.
Sudden Sensorineural Hearing Loss: A Medical Emergency
A specific and critical subset of sensorineural hearing loss is sudden sensorineural hearing loss (SSHL), defined by the NIDCD as an unexplained, rapid loss of 30 dB or more in three contiguous audiometric frequencies within 72 hours or less. It typically affects one ear. People sometimes notice it upon waking, when using a phone, or preceded by a sudden "pop." It may be accompanied by tinnitus, ear fullness, or dizziness.
The NIDCD is explicit: sudden sensorineural hearing loss is a medical emergency. Approximately half of people with SSHL recover some or all of their hearing spontaneously - usually within one to two weeks. But delaying diagnosis and treatment reduces the chance of recovery. The standard treatment is corticosteroids (oral or injected directly through the eardrum into the middle ear), and the NIDCD notes that delaying treatment beyond two to four weeks may result in permanent hearing loss. If you or someone you know experiences a sudden unexplained drop in hearing, see a doctor the same day.
Is Sensorineural Hearing Loss Reversible?
With the exception of SSHL - which may partially or fully resolve with prompt treatment - sensorineural hearing loss is not currently reversible through any approved clinical treatment. The cochlear hair cells of the human inner ear do not regenerate once damaged. This is fundamentally different from most other sensory cells in the body, and it is why noise-induced and age-related sensorineural hearing loss are permanent.
Management focuses on maximizing the hearing that remains. Hearing aids are the primary intervention for mild to moderately severe sensorineural hearing loss. For severe to profound loss, cochlear implants - surgically implanted devices that bypass the damaged hair cells and stimulate the auditory nerve directly - have restored functional hearing in over one million people worldwide. Gene therapy and cell therapy approaches are being actively researched and show early promise, but remain in clinical trial phases as of 2026. For a full discussion of the treatment and reversal landscape, see our guide Can Hearing Loss Be Reversed? What the Research Says.
Conductive Hearing Loss
Conductive hearing loss occurs when sound is physically prevented from traveling through the outer or middle ear to reach the inner ear. The cochlea and auditory nerve may be entirely intact and functioning - the problem is in the mechanical delivery system that gets sound there. This is why, unlike sensorineural hearing loss, many cases of conductive hearing loss are treatable and sometimes fully reversible.
The AAFP identifies cerumen (earwax) impaction, otitis media (middle ear infection), and otosclerosis as the three leading causes of conductive hearing loss. ENT Health (American Academy of Otolaryngology–Head and Neck Surgery Foundation) provides a comprehensive list of additional causes.
What Causes Conductive Hearing Loss
Blockages and Structural Problems of the Outer Ear
Earwax (cerumen) impaction is one of the most common and most easily treated causes of conductive hearing loss. Earwax normally migrates out of the ear canal on its own, but in some people it accumulates and presses against the eardrum, reducing sound transmission. AAFP data show that cerumen impaction may affect up to 30% of older adults and can significantly worsen existing age-related hearing loss. It is treatable through professional microsuction, irrigation, or cerumenolytic drops.
Foreign objects in the ear canal, especially common in young children, can block the ear canal and produce conductive hearing loss. Removal by a healthcare provider restores normal hearing.
Exostosis (surfer's ear) refers to abnormal new bone growth in the ear canal, most often seen in people with prolonged cold water exposure. As the bony growth narrows the canal, it progressively impairs sound passage and increases the risk of earwax and water trapping.
Congenital malformations of the outer ear or ear canal (atresia) - present from birth - can physically prevent sound from reaching the middle ear.
Infections, Structural Damage, and Bone Disorders
Otitis media - infection or inflammation of the middle ear — is the most common cause of conductive hearing loss in children. The accompanying fluid buildup behind the eardrum reduces its ability to vibrate. Otitis media with effusion (fluid without active infection, sometimes called "glue ear") is particularly prevalent in young children and can cause significant temporary hearing loss. Treatment ranges from watchful waiting, to antibiotics for bacterial infection, to surgical drainage and placement of ventilation tubes (grommets).
Perforated eardrum - a hole in the tympanic membrane caused by infection, trauma, or severe eustachian tube dysfunction - reduces the eardrum's ability to vibrate and can allow fluid into the middle ear. Many perforations heal on their own; others require surgical repair (tympanoplasty).
Otosclerosis is an inherited condition in which abnormal bone growth causes the stapes (the innermost of the three middle ear bones) to fuse with surrounding structures, preventing it from vibrating freely. According to NCBI StatPearls, otosclerosis is twice as common in women and typically presents in early adulthood with a gradual onset of bilateral conductive hearing loss. It is the leading cause of conductive hearing loss in adults without a history of ear infections or middle ear fluid. Treatment is hearing aids or surgical repair via stapedectomy.
Cholesteatoma is an abnormal, destructive collection of skin cells in the middle ear space. ENT Health describes it as locally destructive - it can erode the ossicles (the three middle ear bones) and surrounding bone, causing progressive conductive hearing loss and other serious complications. Surgical removal is required.
Ossicular chain disruption - damage to the malleus, incus, or stapes from trauma, infection, or cholesteatoma - disrupts the mechanical transmission of vibration from the eardrum to the inner ear and causes significant conductive hearing loss. Surgical reconstruction of the ossicular chain (ossiculoplasty) may restore hearing.
Eustachian tube dysfunction - failure of the tube connecting the middle ear to the back of the throat to equalize pressure - can lead to fluid accumulation behind the eardrum, ear pain, and conductive hearing loss. It is commonly associated with allergies, upper respiratory infections, and altitude changes.
How Is Conductive Hearing Loss Treated?
The treatment pathway for conductive hearing loss depends directly on the underlying cause - which is why diagnosis by a healthcare provider is essential rather than assuming the cause. Most causes are highly treatable:
When surgery or medical treatment is not possible or does not fully restore hearing, hearing aids - including conventional hearing aids and bone-anchored hearing devices - are effective management tools. The important distinction from sensorineural loss is that for many causes of conductive hearing loss, normal or near-normal hearing can be restored entirely through appropriate intervention.
Mixed Hearing Loss
Mixed hearing loss is a combination of sensorineural and conductive hearing loss occurring simultaneously in the same ear. It involves both damage to the inner ear or auditory nerve (the sensorineural component) and a problem in the outer or middle ear that is obstructing or degrading the incoming sound (the conductive component).
As Cleveland Clinic explains, mixed hearing loss can develop in several ways. A person with pre-existing age-related sensorineural hearing loss who then develops a middle ear infection now has a mixed hearing loss. Someone with an inherited predisposition to otosclerosis may develop cochlear involvement over time, adding a sensorineural element to what began as a purely conductive condition. Severe head trauma can damage multiple parts of the auditory system simultaneously.
How Mixed Hearing Loss Is Diagnosed and Managed
Audiological evaluation - specifically an audiogram that tests both air conduction and bone conduction thresholds - is the primary diagnostic tool for distinguishing mixed hearing loss. The "air-bone gap" (a difference in hearing threshold between air conduction and bone conduction at the same frequency) is the hallmark of a conductive component on an audiogram. When air-bone gaps are present alongside elevated bone conduction thresholds that indicate inner ear damage, mixed hearing loss is confirmed.
Management of mixed hearing loss typically addresses both components, often in sequence. The conductive element - if treatable - is usually addressed first through medical or surgical intervention. The sensorineural component is then managed with appropriate amplification. In some cases, bone-anchored hearing aids (BAHAs) are particularly well suited for mixed hearing loss, as they bypass the outer and middle ear entirely and deliver sound vibration directly to the cochlea through the skull bone.
Auditory Neuropathy Spectrum Disorder (ANSD)
Auditory neuropathy spectrum disorder (ANSD) is the least common of the four types and, for many people, the least familiar. It is also one of the most diagnostically challenging, because standard hearing test results can appear deceptively normal or misleading without the right combination of tests.
ANSD is characterized by disrupted transmission of sound signals from the inner ear to the brain via the auditory nerve - not simply reduced volume. In ANSD, the outer hair cells of the cochlea typically function normally, and sounds enter the ear at normal levels. The problem lies in how that information is organized and transmitted. The result is speech perception that is far worse than pure-tone hearing thresholds alone would predict. As described by the National Organization for Rare Disorders (NORD), hearing thresholds may range from normal to severe, yet the person's ability to understand speech - especially in noise - is disproportionately impaired.
Who ANSD Affects
ANSD can affect adults and children alike, though it is most frequently identified in infants and young children through newborn hearing screening programs, which can detect the characteristic audiological pattern (present otoacoustic emissions with absent or abnormal auditory brainstem responses). NORD estimates the general population incidence at approximately 1 to 3 per 10,000 births. Among children with identified permanent sensorineural hearing loss, research studies have found ANSD prevalence ranging from 5% to as high as 14%.
Known risk factors for ANSD include: premature birth and low birth weight, hyperbilirubinemia (jaundice) in newborns, anoxia (oxygen deprivation) at or around birth, certain genetic mutations, and exposure to ototoxic drugs in early life. In adults, ANSD may result from immune conditions, neurological diseases, or other systemic conditions affecting nerve function.
Diagnosis and Management of ANSD
Diagnosing ANSD requires a specialist audiological evaluation that goes beyond a standard hearing test. Key findings include: normal or near-normal otoacoustic emissions (OAEs) - confirming outer hair cell function - alongside absent or severely abnormal auditory brainstem responses (ABRs), which indicate disrupted neural transmission. Standard audiometry alone is insufficient for diagnosis.
Management of ANSD is individualized and may include hearing aids (which help some but not all people with ANSD), cochlear implants (which show significant benefit in many cases, as they bypass the disrupted transmission pathway and stimulate the auditory nerve directly), auditory training, and other communication support strategies. Outcomes are highly variable and depend on the underlying cause and individual neurological profile.
The Four Types of Hearing Loss: A Side-by-Side Summary
Degree of Hearing Loss: The Other Dimension
Type of hearing loss tells you where the problem originates. Degree of hearing loss tells you how much hearing has been lost. These are two separate dimensions - and both are needed to fully understand a person's hearing health.
Audiologists measure degree of hearing loss in decibels of hearing level (dB HL), using a standardized scale. The classifications used by the WHO and Global Burden of Disease are widely adopted in clinical practice:
Any hearing loss above 35 dB HL in the better-hearing ear is classified as "disabling" by the WHO and Global Burden of Disease - the level at which hearing difficulty begins to substantially affect communication and quality of life. This threshold matters because it defines who, globally, is counted as requiring hearing rehabilitation services.
It is also worth noting that hearing loss can affect one ear (unilateral) or both ears (bilateral), and can affect frequencies differently across the range. Age-related sensorineural hearing loss, for example, typically produces a "high-frequency sloping" pattern on an audiogram - where high-pitched sounds are affected far more than low-pitched ones - because the hair cells at the base of the cochlea (which process high frequencies) are the most vulnerable to cumulative damage.
How the Type of Hearing Loss Is Diagnosed
Determining the type of hearing loss is the audiologist's first clinical task - and it requires evaluation beyond simply measuring how loud a sound needs to be before you can hear it. The key diagnostic tools are:
Pure-Tone Audiometry (The Audiogram)
The foundation of hearing assessment. The audiologist measures both air conduction (how well sound travels through the outer and middle ear into the inner ear) and bone conduction (how well the cochlea and auditory nerve respond when the skull bone is vibrated directly). An "air-bone gap" - a difference between the two thresholds at the same frequency in the same ear - is the diagnostic signature of a conductive component. The audiogram plots all results across frequencies and volumes, producing a map of the person's hearing.
Weber and Rinne Tuning Fork Tests
Bedside clinical tests that provide rapid information about the type of hearing loss. In the Weber test, a vibrating tuning fork placed on the forehead reveals whether sound lateralizes to one ear - indicating either a conductive loss in that ear or a sensorineural loss in the opposite ear. In the Rinne test, the fork is placed on the mastoid bone (behind the ear) and then next to the ear canal: if bone conduction is louder than air conduction, a conductive hearing loss of at least 30 dB is present. These tests are especially useful for evaluating unilateral hearing loss (NCBI StatPearls).
Tympanometry
A test that measures the mobility of the eardrum and the pressure in the middle ear by introducing small pressure changes into the sealed ear canal. Tympanometry is particularly useful for identifying fluid behind the eardrum, eardrum perforations, and eustachian tube dysfunction - all causes of conductive hearing loss. Results are plotted on a tympanogram, with a flat trace ("Type B") indicating middle ear fluid or a perforated eardrum.
Otoacoustic Emissions (OAEs) and Auditory Brainstem Response (ABR)
OAE testing measures sounds produced by the outer hair cells of the cochlea in response to stimulation - if the outer hair cells are intact and functioning, they produce these tiny echo-like sounds. ABR testing measures the electrical activity of the auditory nerve and brainstem in response to sound. Together, these tests are essential for diagnosing ANSD (present OAEs + absent ABR), for evaluating hearing in infants and individuals who cannot respond behaviorally, and for identifying the site of lesion in complex or unusual cases.
A comprehensive audiological evaluation typically combines all of the above, along with a physical examination of the ear canal and eardrum using an otoscope, and a detailed case history covering noise exposure, medical history, medications, and family history of hearing loss. Together, these tools provide a complete and accurate picture of the type, degree, and likely cause of any hearing loss present.
The Two Most Common Subtypes: Presbycusis and Noise-Induced Hearing Loss
Within the broader category of sensorineural hearing loss, two subtypes account for the vast majority of cases in the U.S. adult population. Understanding them specifically helps with both recognition and prevention.
Presbycusis (Age-Related Hearing Loss)
Presbycusis is the most prevalent cause of sensorineural hearing loss - and the most common cause of hearing loss overall. The NIDCD reports that approximately one in three Americans between 65 and 74 has hearing loss, rising to nearly half of those over 75. Presbycusis occurs because the cochlear hair cells and supporting structures in the inner ear deteriorate progressively over a lifetime of use. The loss begins at the highest frequencies and works its way down, which is why it often goes unnoticed in its early stages - the highest frequencies affected first are above the range critical for everyday speech.
The cause of presbycusis is multifactorial: genetics, cumulative lifetime noise exposure, cardiovascular health, and systemic conditions such as diabetes all play a role. There are currently no proven preventive measures for the underlying biological aging process, though protecting hearing from noise and managing cardiovascular risk factors may slow its progression.
Noise-Induced Hearing Loss (NIHL)
Noise-induced hearing loss is the second most common cause of sensorineural hearing loss globally, and - critically - it is almost entirely preventable. A 2023 review in the Journal of Clinical Medicine estimated that NIHL affects approximately 5% of the world's population. The CDC and NIDCD found that nearly one in four U.S. adults aged 20 to 69 shows audiometric signs consistent with NIHL - many with no reported workplace noise exposure, suggesting a significant recreational contribution from personal audio devices, concerts, and other high-noise environments.
NIHL occurs when exposure to sounds of 85 decibels or above causes physical damage to the cochlear hair cells - either from a single extremely loud event (such as an explosion) or from cumulative exposure over time. The damage is permanent. The characteristic audiometric "notch" at 4,000 Hz on an audiogram is a hallmark finding of NIHL.
Noise-induced hearing loss is permanent, painless, and preventable. Because it develops gradually and without immediate discomfort, most people are unaware it is happening until significant and irreversible damage has already occurred.
National Institute for Occupational Safety and Health (NIOSH) / CDCWhatever the Type - Safety at Home Requires More Than Hearing Aids
For people with any type of significant hearing loss, hearing aids or cochlear implants address the core communication challenge effectively. But they don't address every situation. At night, hearing aids come out. In noisy environments, even well-fitted aids have limits. And standard home safety devices - smoke alarms, carbon monoxide detectors, doorbells, baby monitors - were not designed with hearing loss in mind.
High-frequency hearing is precisely the range that deteriorates first in sensorineural and mixed hearing loss. Standard smoke alarms emit high-pitched tones that fall squarely in that range. For people with significant high-frequency loss, those alerts may be substantially reduced or completely inaudible - particularly during the night hours when aids are removed and sleep masks natural environmental awareness.
- Smoke and fire alarms - high-pitched tones, first range affected in age-related loss
- Carbon monoxide detectors - same frequency range, same vulnerability
- Doorbell - often missed when in another room or without aids
- Telephone and video calls - especially with hearing aids removed
- Baby monitor - critical alert easily missed in sleep or another room
- Alarm clocks - standard audio alarms ineffective without aids
Purpose-built alerting devices for hearing loss close these gaps by translating important sounds into signals that can be seen or felt rather than only heard. Vibrating bed shakers respond to smoke alarms at night. Strobe-equipped doorbell receivers flash when someone arrives. Wristband receivers vibrate and display which sensor has triggered. Whole-home systems connect all of these to a single network, so any alert in the house reaches you in any room.
These tools work independently of whether you're wearing your hearing aids, are in a different part of the house, or are asleep. For people managing hearing loss of any type, they are a practical and important layer of safety that amplification alone cannot provide. You can explore Bellman's full range of alerting solutions, TV listening systems, and hearing accessories at bellman.
Signs that your type of hearing loss may not yet be identified
Any of these is a reason to schedule a comprehensive audiological evaluation.
- You hear speech but struggle to understand it, especially in noise
- You've had a hearing test but were never told the type of loss
- You experienced a sudden drop in hearing in one or both ears
- One ear seems significantly worse than the other
- You've had frequent ear infections or chronic ear problems
- You have ringing, buzzing, or hissing in one or both ears
- You've had significant noise exposure at work or recreationally
- You've taken medications known to affect hearing
- A family member was diagnosed with hearing loss at a young age
- Your last hearing evaluation was more than three years ago
The Bottom Line
Hearing loss is not one thing. Sensorineural hearing loss, conductive hearing loss, mixed hearing loss, and auditory neuropathy spectrum disorder each arise from different parts of the auditory system, have different causes, different trajectories, and crucially, different treatment options. For conductive hearing loss in particular, the distinction matters enormously: many people are living with manageable or even reversible hearing loss that has simply never been accurately diagnosed.
The path to the right treatment, the right tools, and the right expectations starts with knowing which type of hearing loss you have - and that starts with a comprehensive audiological evaluation. The ASHA recommends hearing screening at least every decade up to age 50, and every three years after that. For anyone with risk factors - noise exposure, family history, ototoxic medications, or any of the symptoms listed above - earlier evaluation is the right move.
For a broader view of living well with hearing loss - including the impacts on daily life, cognitive health, safety, and the tools available to address them - see our complete guide: The Complete Guide to Living with Hearing Loss (2026).
Close the safety gaps that hearing aids alone can't cover.
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Sources: National Institute on Deafness and Other Communication Disorders (NIDCD) - Age-Related Hearing Loss; Noise-Induced Hearing Loss; Sudden Deafness; Quick Statistics About Hearing · Centers for Disease Control and Prevention (CDC) - Types of Hearing Loss in Children; Noise-Induced Hearing Loss; U.S. Adults Show Signs of Noise-Induced Hearing Loss (Vital Signs, 2017) · Johns Hopkins Medicine - Types of Hearing Loss · Cleveland Clinic - Sensorineural Hearing Loss (reviewed November 2024); Conductive Hearing Loss (reviewed 2025) · American Academy of Family Physicians (AAFP) - Differential Diagnosis and Treatment of Hearing Loss; Hearing Loss in Older Adults · ENT Health (American Academy of Otolaryngology–Head and Neck Surgery Foundation) - Conductive Hearing Loss · NCBI StatPearls - Sensorineural Hearing Loss; Conductive Hearing Loss; Audiogram Interpretation; Pure Tone Evaluation; Weber Test · National Organization for Rare Disorders (NORD) - Auditory Neuropathy Spectrum Disorder · Journal of Clinical Medicine - Noise-Induced Hearing Loss (2023) · PMC / Audiological Studies - Prevalence of Auditory Neuropathy Spectrum Disorder in Sensorineural Hearing Loss Populations · NCBI StatPearls - Audiometric Testing · University of Iowa Head and Neck Protocols - Sensorineural and Conductive Hearing Loss; How to Read an Audiogram · World Health Organization (WHO) - Deafness and Hearing Loss Fact Sheet (March 2026) · Hearing Loss Association of America (HLAA) · American Speech-Language-Hearing Association (ASHA).
This article is for informational purposes only and does not constitute medical advice. Consult a licensed audiologist or healthcare provider for a personalized hearing evaluation and treatment recommendations.
